Closing device for housing

ABSTRACT

This invention relates to a closing device for a housing of an air filter that can be closed with a housing cover. The assembly process is to be simplified and accelerated, while the number of parts required is to be reduced at the same time. According to the invention, this is achieved in that the housing cover and the housing can be connected to one another by means of a locking frame which surrounds the housing cover and the housing in the region of the housing edge, said locking frame being positionable in closed position by means of translatory motion, in which position it presses the housing cover onto the housing edge.

BACKGROUND

The invention relates to a closing device for an essentially box orshell-shaped housing that can be closed by a housing cover foraccommodating objects, particularly an air filter housing for a motorvehicle or the like, displaying a housing edge with a seal, onto whichthe housing cover connectable to the housing can be placed.

The air filter housing accommodates an air filter and is provided withthe necessary feed and discharge lines. Mounted on the edge, between thehousing cover and the housing, is a rubber seal, which is preferablydesigned as a sealing ring in order to achieve a tight fit between theair filter housing and the housing cover when the housing cover is inplace.

It is familiar practice for securing the housing cover on the housing touse several clamps, screws, plastic clips or the like as connectorsdistributed around the circumference, in order to obtain a tightconnection between the two components. The connectors have to be mountedindividually in a time-consuming process during assembly. The clips orclamps, which are preferably made of plastic, can snap off and may thenhave to be replaced. Screws first have to be positioned and then screwedin using a tool. All these types of connectors can be dropped duringassembly and have to be picked up, this not being possible withoutfurther ado in an automated process. In any case, several manualoperations are necessary in order to implement the circumferentialfastening necessary for a tight connection. On the whole, assembly isvery time-consuming when using any of the fastening methods familiarfrom the prior art. In addition, tools are necessary, which may also bedropped.

SUMMARY OF THE INVENTION

The object of the present invention to is facilitate and accelerate theassembly of an air filter housing.

According to the invention, the object is solved in that the housingcover and the housing can be connected to one another by means of alocking frame which surrounds the housing cover and the housing in theregion of the housing edge, said locking frame being positionable inclosed position by means of translatory motion.

During final assembly of the air filter, the housing cover is placed onthe seal of the housing edge and pressed down, so that the housing covercovers the entire edge of the housing. Axial force is then applied todisplace the locking frame relative to the housing cover and the housingand move it into the closed position. In this position, the lockingframe reaches around the housing and the housing cover in the manner ofa clamp, pressing the two parts together in tightly sealing fashion.

The locking frame can be designed either as a closed profile, or as anopen or slotted profile.

Due to the fact that the housing cover is not moved in relation to thehousing during assembly, only the locking frame being moved relative tothe stationary housing cover/housing, the sealing ring located in thehousing edge is not subjected to any shearing forces that could resultin displacement of the seal and thus in leaks. Consequently, the closingdevice according to the invention permits simple, two-handed assembly,without tools and without a need for any other connectors, such asscrews, clips or hooks. In the same way, the housing cover can bedetached from the housing without tools. In the simplest case, only twocomponents are necessary, namely the air filter housing and the unitcomprising the locking frame/housing cover. Finally, the closing deviceaccording to the invention permits greater freedom in terms of designand geometry, as no fastening elements or devices for this purpose haveto be provided in the edge area.

If the locking frame is not designed as a closed profile, but isprovided with a joint at one point, the locking frame can be ofpartially elastic design, allowing it to be bent open in order tosimplify assembly.

Assembly is particularly facilitated if the locking frame is designed asa one-piece, closed profile and to be torsion-resistant. It has provento be particularly expedient with this design that at least the edge ofthe housing cover can be connected to a side of the locking frame thatis on top in installed position, that the housing cover is mounted in amanner permitting relative movement in the locking frame and that a sideof the locking frame that is on the bottom in installed position can beplaced on the housing edge and the locking frame connected to thehousing by means of relative displacement. During pre-assembly, thisdesign makes it possible first to insert the housing cover into thelocking frame in such a way that it is mounted in a manner permittingrelative movement in the locking frame. During final assembly of the airfilter, the unit comprising the housing cover and the locking frame isplaced on the housing edge, pressed down and fixed in place bydisplaying the locking frame in relation to the stationaryhousing/housing cover.

In order to prevent unintentional relative displacement of the lockingframe from the closed position, snap-in elements can be provided betweenthe housing cover and the locking frame and/or the locking frame and thehousing, these elements engaging each other or reaching behind eachother when in locked position.

In a preferred configuration, one or more snap-in tabs are provided onthe housing cover, these having run-up bevels that extend in thedirection of thrust and snap-in cams that run essentially perpendicularto the direction of thrust and engage a snap-in recess provided on thelocking frame when in closed position.

The snap-in elements are customarily of elastic design, so as to achievea more easily separable connection between the housing, the housingcover and the locking frame.

Like the air filter housing, the locking frame is preferably designed asan injection-moulded part, as plastics can be moulded easily and asrequired. Alternatively, the parts can be made of metal, or combinationsof different materials can also be used.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in the drawings on the basis of a preferredpractical example. The figures show the following:

FIG. 1 A perspective view of a locking frame according to the inventionwith inserted housing cover,

FIG. 2 A perspective view of the locking frame,

FIG. 3 A perspective view of the housing cover,

FIG. 4 A perspective view of the air filter housing to which the housingcover can be fastened using the locking frame,

FIG. 5 A top view of the locking frame and the housing cover as per FIG.1, placed on an air filter housing,

FIG. 6 A section along line VI—VI in FIG. 5 with the locking frame inopen position,

FIG. 6 a A section along line VI—VI in FIG. 5 with the locking frame inclosed, assembled position,

FIG. 7 A section along line VII—VII in FIG. 5,

FIG. 8 A section along line VIII—VIII in FIG. 5, and

FIG. 9 A top view of the housing cover without locking frame.

DESCRIPTION OF THE INVENTION

Accordingly, the air filter housing consists of an essentiallybox-shaped housing 1 for accommodating an air filter not shown indetail. Housing 1 can be sealed in airtight fashion by housing cover 2,which is placed on housing edge 3 and can be connected to housing 1 bymeans of locking frame 4 according to the invention.

According to FIG. 3, housing cover 2, which is designed as an injectionmoulded part, is provided with a dome-shaped arch with an all-roundshoulder 5 at the bottom end in installed position. In installedposition, this shoulder 5 rests on housing edge 3. The perimeter ofshoulder 5 is provided with an integrally moulded housing cover web 6extending downwards. This housing cover web 6 reaches over housing edge3 when in installed position.

FIG. 2 shows the structure of locking frame 4. Locking frame 4 isdesigned as a collar-like, closed profile frame reaching over shoulder 5and housing cover web 6 with an upper section 7 that can be placed onshoulder 5 and from which an all-round locking frame web 8 extendsdownwards at an angle to upper section 7. Upper section 7 is providedwith a cut-out 9, through which the dome-shaped arch of housing cover 2can pass.

During pre-assembly, locking frame 4 is placed onto housing cover 2 fromabove, so that upper section 7 of locking frame 4 rests on shoulder 5 ofhousing cover 2. When locking frame 4 is pressed on, it snaps overhousing cover 2, as described in more detail below. In installedposition, housing cover 2 is mounted in locking frame 4 in slidingfashion, preferably over a range of 20 mm.

Outward-protruding projections 10, with recesses 10 a between them, areprovided at regular intervals on two opposite sides of housing cover web6—referred to below as the longitudinal sides. These projections 10 haveoutward-protruding shoulders 10 a at the upper end.

Provided below housing edge 3 on housing 1 is an outward-protruding,all-round rib 12, which is interrupted at regular intervals on theopposite longitudinal sides in order to form housing tabs 13 atrecurring intervals. When housing cover 2 is in place, these housingtabs 13 are in alignment with projections 10 on housing cover web 6 (seeFIG. 6).

It can be seen from FIG. 7 that, in installed position, shoulders 10 brest in sliding fashion on a first, inward-protruding, all-round rib 15of locking frame 4, which is integrally moulded on a leg 20 runningvertically in installed position. This leg is of resilient design, inorder to allow locking frame 4 to be snapped onto housing cover 2.Integrally moulded on leg 20 of locking frame 4, at a distance below thefirst rib 15 and space apart from each other, are several,inward-protruding frame tabs 16.

FIGS. 6 and 6 a show how, when placing housing cover 2 on housing edge3, locking frame 4 is moved, by exerting axial thrust in the directionof arrow A, from the open position illustrated in FIG. 6 to the closedposition shown in FIG. 6 a, in which it reaches around the circumferenceof both housing cover 2 and housing 1.

After executing closing motion A, frame tabs 16 reach under housing tabs13 under pre-tension, meaning that they are designed with aninterference fit. Housing tabs 13 and frame tabs 16 are provided withrun-up bevels of complementary design on their ends lying at the frontin the direction of thrust, in order to allow them to move relative toeach other without tilting and to realise the interference fit ofhousing cover 2 on housing 1. As the frame tabs are provided around theentire circumference of locking frame 4, they also reach below all-roundrib 12 of housing 1 on its lateral sides, there thus being acircumferential interference fit between housing 1 and housing cover 2on up to three sides in closed position.

FIG. 7 shows sealing ring 17, which is located between housing cover 2and housing edge 3. It is held in place on housing edge 3 by means of ashoulder provided on the latter.

As can be seen by looking at FIGS. 1, 4, 8 and 9, three tabs 18, spacedapart from each other, are integrally moulded on the rear end of housingcover 2. In order to fix the housing cover in place when housing cover 2is placed on housing 1, these tabs 18 are inserted into correspondinglydesigned cut-outs 21, which are provided at appropriate points on asnap-in web 22 of the air filter housing that projects upwards beyondhousing edge 3 and is offset slightly towards the outside.

The interaction of tabs 18 and snap-in recess 19 is illustrated in anenlarged view in FIG. 8, which shows a lateral cross-section along lineVIII—VIII in FIG. 5. When locking frame 4 has been slid into closedposition, projections 23, provided on the underside of snap-in recess19, reach behind the upper end of the rear side of snap-in web 22.Projections 23 are integrally moulded on snap-in recess 19 in resilientfashion and can be raised via a projection 24, integrally moulded on theupper side of snap-in recess 19, in order to separate the snap-inconnection between snap-in web 22 and downward-protruding projections23. Preferably, two downward-protruding projections 23 and correspondingupward-protruding projections 24 are provided, so that the snap-inconnection can be separated with two hands.

The locking frame according to the invention permits simple assemblywithout tools. No clips, screws or hooks are needed that have to bepositioned around the circumference between the housing and the housingcover. The prior art required seven screws or retaining clips forfastening, meaning that the total number of parts has been reduced froma total of nine to two, namely the housing and the housing cover withthe locking frame fitted on it. As no retaining clips are requiredaround the circumference, the design of the housing and housing cover ismore variable and can be better adapted to prevailing conditions.

List of reference numbers  1 Housing  2 Housing cover  3 Housing edge  4Locking frame  5 Shoulder  6 Housing cover web  7 Upper section  8Locking frame web  9 Cut-out 10 Projection 10a Cut-out 10b Shoulder 12Rib 13 Housing tab 15 First rib 16 Frame tab 17 Sealing ring 18 Snap-intab 19 Snap-in recess 20 Leg 21 Cut-out 22 Snap-in web 23 Projection 24Projection

1. Closing device for an essentially box or shell-shaped housing that can be closed by a housing cover comprising a housing cover including a housing with a housing edge with a seal onto which said housing cover is connectable to said housing, and a closed profile locking frame, characterised in that the housing cover and the housing can be connected to one another by means of said closed profile locking frame where said locking frame surrounds said housing cover around the entire circumference of the housing in the region of the housing edge, and wherein said locking frame is positioned into a closed position by means of a translatory motion, which presses said housing cover onto said housing edge.
 2. Closing device as per claim 1, characterised in that the edge of the housing cover can be connected to a side of the locking frame that is on top in installed position, in that the housing cover is mounted in a manner permitting relative movement in the locking frame and in that a side of the locking frame that is on the bottom in installed position can be placed on the housing edge and the looking frame connected to it by means of translatory motion.
 3. Closing device as per claim 1, characterised in that snap-in elements acting between the locking frame and the housing cover and/or the locking frame and the housing are provided.
 4. Closing device as per claim 1, characterised in that snap-in elements preventing relative displacement of the locking frame and the housing cover are provided between the locking frame and the housing cover.
 5. Closing device as per claim 1, characterised in that the locking frame can be connected to the housing and/or the housing cover in separable fashion.
 6. Closing device as per claim 1, characterised in that the locking frame is designed as an injection-moulded plastic part.
 7. Closing device as per claim 1, characterised in that snap-in elements are provided between the housing cover and the housing, which prevent relative displacement between the housing cover and the housing in closed position. 